Self-cleaning door mat



0. o. SWANSQN SELF-CLEANING DOOR MAT Sept. 7, 1948.

2 Sheets-Sheet 2 Filed Nov. 50, 1944 I INVENTOR. C424 0. 501/4400 BY flaw/ 6,4

Patented Sept. 7, 1948 UNITED STATES PATENT OFFICE 2,448,931 SELF-CLEANING noon MAT Carl 0. Swanson, Minneapolis, Minn. Application November 30, 1944, Serial No. 565,873

8 Claims. 1

This invention relates to door mats, and the main object is to provide a novel, efficient and practical construction of door mat including mechanically moving and power actuated elements which are operative to automatically scrape and clean the soles of shoes worn by people entering the building in which the mat apparatus has been installed.

The invention is particularly intended and designed for use in ofilce buildings, hospitals, stores,

banks, churches, theaters, and similar buildings,

patronized by the general public. In such buildings, as is well known, the amount of mud, slush. and dirt carried into and deposited on the floor by pedestrians, particularly in rainy and snowy weather, is substantial, and not only results in unsightly soiling and wear of the floor surface but is very unsanitary, often produces a dangerously slippery condition, and of course frequently results in soiling fixtures, walls, furniture and merchandise, all of which requires labor and expense to keep clean.

To overcome these and other objections I provide a door mat having a series of endless belts over which the people walk and the apparatus is installed in the floor immediately inside the outer building door so that the building patrons are compelled to traverse it as they enter; and, in wet or slushy weather these belts are set in motion, by suitable applications of power, to produce a scrubbing action on the shoes ,or rubbers of those passing over. As further features of the invention I provide the mat with fixed grill bars, between the belts, and upon which the pedestrians weight is primarily borne; and a receptacle through which the lower runs of the belts are operated so as to deposit dirt therein and be washed by water or other cleansing solution in the receptacle.

Still other and more detailed features and characteristics of the invention will be disclosed in the course of the following specification, reference being had to the accompanying drawings,

wherein:

Fig. 1 is a plan View of the door mat showing it as installed in a floor inside a revolving door, the latter and its adjacent wall portions being shown in section.

Fig. 2 is an enlarged sectional elevation on the line 22 as in Fig. 1.

Fig. 3 is a cross sectional elevation on line 33 in either Fig. 1 or Fig. 2. l

Fig. 4 is a longitudinal sectional elevation through a modified form of the apparatus.

Fig. 5 is a cross sectional elevation on line 5-5 in Fig. 4.

Referring to the drawings more particularly and by reference characters A designates the ground floor of a building having a front wall B provided with a revolving door entrance C, as shown in Fig. 1. Immediately inside the entrance C the floor is provided with a rectangular inset frame structure 6 which supports a housing or pan I which depends below the floor surface. Extending longitudinally with respect to the general path of foot travel the frame 6-"l includes a series of transversely spaced. parallel bars 8, disposed in vertical. planes and secured at their ends in the frame, the upper edges of these bars being flush with the floor surface and adapted to engage the feed and support the weight of pedestrians passing in from the door, it being understood that these bars are rigid and stationary in the frame.

Intermediate the bars 8 is a series of flexible belts 9, which are stretched over rollers Ill at opposite ends of the frame, and since the belts are of flexible and preferably elastic material, such as rubber, it will be seen that they will be substantially taut as they travel between the bars. The upper surfaces of these belts are preferably disposed slightly below the levels of the upper edges of the bars 8, but are provided with tapered cleats ll whichnormally projectabove the floor level of the baredges so as to yieldably contact with and thus brush, off or clean the sole surfaces of footwear worn by the pedestrians as they walk over this area of the floor.

The rollers ID are mounted on a pair of shafts I2 and 13, one at each end of the receptacle 1,

and the shaft '2 extends from the receptacle to be driven by a shaft I l through a pair of bevel pinions l5. The shaft I4 is rotated by a motor or other suitable source of power (not shown) and which is started and stopped as weather conditions may require.

Extending both lengthwise and transversely under the upper runs of all the belts 9 is a plate IS, the same being preferably supported by a series of ,end lugs H which engage the shafts l2 and I3 intermediate the belts. The lugs ll which trunnion on the shaft I3 may extend from a separate cross piece Ill adjustably secured to the plate l6 by bolts l9 so that the spacing between the shafts may be slightly adjusted to thereby regulate the tension of the belts as wear and slack may develop.

The plate l6 serves a further and more important purpose, however, and that is to provide 3 yieldable support for the belts throughout their respective spans between the rollers, and this is accomplished by attaching to the plate series of spring bumpers or fingers 20, as shown in Fig. 2, which are firmly attached at their lower and 5 leading ends to the plate while their upper and trailing ends are arched to slidably engage the under surfaces of the upper runs of the belts. With thisrconstruction-it will be evident.-that the belt cleats I l willalwayyand at all :points be held up in effective Wiping contact with the bottom surfaces of the footwear worn by pedestrians, but

that the entire construction will have.-suflicient flexibility so that the persons weight"will""cause' his feet to remain in frictional dormant with:the.i115

slots in the bars and in the side walls in the upper edges of the bars 8 and thus prevent him from being moved or thrown off balance by the travel action of the belts. l

To render the cleaning action of the belts more .effective I cause the.lower runs of the. belts 9 to travel in a bath of water or Otherbleaning fluid which is contained in the receptaclei], and to, providefor the necessary supply and circula- -tion ofjthe fluidiIhave shown a. supply or inlet let pipe '22 is preferably located at the other end and may also serve:.as an overflow draintto maintain. a predetermined level' of the 'fluid-in the receptacle.

"At the right'han'dendof the "device, as shown 0 in Fig- 2, I provide aseries. of wiper. springs'23, one for ,each b'elt. One end of the spring ..is ..anchored, as at 2,4, to the frame, while .the opposite end edge is held in yielding'contact with the :belt. The intermediate part of .the spring .is curved in such a mannerlthat it will yield and causethefree end of the springLtdengage. the ..belt. surface with awiping contact.as it moves "upwardly from the liquid bathabout'the adjacent rollerll], such contact alsoLbeing'of'such nature 40 that it will remove surplus moisture: "from .lthe 'lugs l. I. r

The operation of. the device as. thus; set "forth will nodoubt' be.obvious, but'may'besummarized as follows: UnderQdry orfairlynormal.;weather conditions the device merely serves as an ordinary or conventional'do'or mat, andpeople entering the ..bliildingmay wipe thir feet on 'it'..as..they pass over in;the usual manner. Any dust or 'dirt'so deposited .will .escape downwardly: between the belts 9 and bars8; to bereceive'd in the'pan'l.

When. weather conditions are wet or snowy power is applied'to the 'shaftl.l4' and;water .is admitted into the. pan through..pil 12l. .It is preferable to have the'water .fflow continuously, and as, it then escapes through the overflow. drain .22 'it..carries with it muchof .thefdirt, and'the continued flow of clean water alongi.thebelts .tends'to wash thebelts and keep themclean. It will be noted that this action" is facilitated bythe fact that the water moves along the pan infla direction opposite to the direction in :which.lthe lower or. submerged run. of the belt is operating. As the beltsnow emergefrorri'theirbath they are -wiped off by the spring .wipers'23.

.Th npper. runs of the belts, together-with their projecting lugs, then.move. alongbetween'the upperedges of.the barsg8, and when a person steps on the mat the springs20 .will yield stifliciently so that his weightlis imposed andcarried .directly upon the bars. "Duringl the,period or interval while the foot remainsjn'this position the belt lugsproduce a wiping action on 'theishoe and after the person hastaken'the'few steps necessary to cross"themat'his footwear willbe bottom -terminating in-a trap'i28 through which dirt and other sediment-may be discharged. In

this case, too, the shaft 29 supporting one set of 11011818 30 is driven through bevel pinions 3| by a motor 32. disposed adjacent thereto in a chamber "33formed" at one end of the housing or frame ..structure. :The opposite shaft 34 extends through caising for bea'ringengagement in bearings 35 which, are adjustable at 36 to take up slack in .brush bristlesor tufts 38, instead of thelugs Las showninfli igs. 2- 3, and these bristles. are sufficiently .flexible so that they will yield and vigorously brush off the pedestrians shoes. 'JWith pipeZ I" at one end of the receptacleyvhile an out- 25 yielding support (such as springs 20)' for. the belts this arrangement. it is not necessary to.provide proper and for that reason I permitthe belts to travel in fixed. or rigid channels 39 These channelsarefformed by theupper edge portions of the bars. 8 and horizontal intermediatebarsor plates Mltheedgesof which are welded or otherwise secured to the bars'B. v.Thus the.plates"4'!J not only support the belts but tend to rigidify. the

entire frame construction.

It .will' be. understood that still further modifications may be made in the inventionfwithout departingfrom the spirit..and scope of the appended claims. Having now .therefore fully illustrated and describedpreferredembodiments pedestrian supporting bars, a series of endless power actuatedbelts stretched over rollerslbelow the! floor surfaceand having their. upper runs 'extending'between said bars, said'.bel ts having integrally formed. lugs adapted .to project above the level of.the.upp er edges of the bars to clean pedestrian ,shoes,.a receptacle under-and substantially coextensive with ..theilength ofthe "frame, .fiuid supply means to' the receptaclefor washing the belts. and. lugs as .the' belts travel their under runs between said rollers,.an'd means for wiping surfaces of the belts arid'lugs after they have been washed and before they'return" to shoe cleaning elevation.

2. A self=c1eaning door mat comprising a frame set in a floor substantially flu'shwiththe surface thereof, said frame comprising spaced parallel, pedestrian supporting bars, -a'--seriesof endless power actuated." b'elts stretched over-"roll" ers below the floor surface and having their up- 65 per-runs extendingibetween said barsgsaid belts shaving :iriteg-rallydormed lugs adapted rtorrpro- 'jectvabovelthe' level of theupper edges of the bars to clean pedestrian shoes;-at-receptacle under .and substantially coextensive "with the length of the frame, fluid supply means-.tonthe recepv.tacle. forwashing the. belts and. lugs .as :thesbelts travel their undenruns-between said. rollers,. and meansfor wiping surfaces. of the belts.and..lugs after they have been washedan'dbefore they return to shoe cleaning elevation, saidwiping means comprising a series of flexible devices rigidly mounted with respect to the frame and having yieldable contact with the respective belts to remove foreign material from the surfaces thereof and from the lugs thereon as the belts move therepast.

3. In a self-cleaning door mat, a series of spaced, parallel bars mounted substantially flush with the surface of a floor to support pedestrians walking thereover, a series of power actuated endless belts mounted on rollers below opposite ends of the bars and with their upper runs extending horizontally between the bars, shoe scraping lugs extending from the outer surfaces of the belts, a fluid receptacle disposed below the bars and extending horizontally and substantially coextensively therewith whereby the entire lower runs of the belts between the rollers may travel in a fluid bath in the receptacle and thereby loosen foreign matter adhering to the belt and lug surfaces, and means for removing bath fluid from the exposed belt and lug surfaces before they are returned to the upper shoe cleaning run of travel.

4. In a self-cleaning door mat, a series of spaced, parallel bars mounted substantially flush with the surface of a floor to support pedestrians walking thereover, a series of power actuated endless belts mounted on rollers below opposite ends of the bars and with their upper runs extending horizontally between the bars, shoe scraping lugs extending from the outer surfaces of the belts, a fluid receptacle disposed below the bars and extending horizontally and substantially coextensively therewith whereby the entire lower runs of the belts between the rollers maytravel in a fluid bath in the receptacle and thereby loosen foreign matter adhering to the belt and lug surfaces, and means for removing bath fluid from the exposed belt and lug surfaces before they are returned to the upper shoe cleaning run of travel, said receptacle being provided with fluid supp-1y and outlet means operative to maintain a fluid supply of constant level whereby the lower runs of the belts will travel at a predetermined depth in the fluid bath.

5. In a self-cleaning floor mat, a series of spaced, parallel bars rigidly mounted in a floor with their upper edges substantially flush with the floor surface, a series of power actuated endless belts mounted on end rollers below the floor surface and with their upper runs extending longitudinally between the bars, shoe scraping lugs extending from the outer surfaces of the belts and so formed as to normally project above the level of the top edges of the bars, and means in substantially coextensive supporting contact with the upper run of each belt, such means being yieldable under direct foot pressure on the belt lugs under the area of greatest foot pressure while permitting other parts of the supporting means to also maintain the belt lugs in cleaning contact with shoe surfaces slightly above the upper bar edges.

6. In a self-cleaning floor mat, a series of spaced parallel bars rigidly mounted in a floor with their upper edges substantially flush with the floor surface, a series of power actuated endless belts mounted on end rollers below the floor surface and with their upper runs extending longitudinally between the bars, shoe scraping lugs extending from the outer surfaces of the belts and so formed as to normally project above the level of the top edges of the bars, and means for yieldably supporting the upper runs of each belt, said supporting means being substantially coextensive with the shoe engaging length of the belt, and being yieldable as to any given belt length pressure area without yielding as to remaining belt length areas.

7. In a self-cleaning floor mat, a series of spaced, parallel bars rigidly mounted in a floor with their upper edges substantially flush with the floor surface, a series of power actuated endless belts mounted on end rollers below the floor surface and with their upper runs extending longitudinally between the bars, shoe scraping lugs extending from the outer surfaces of the belts and so formed as to normally project above the level of the top edges of the bars, and means including a, series of pressure responsive supporting devices extending under and throughout the upper run of each belt and being operative to hold all belt lugs above the top level of the bars except where foot pressure at a given area is sufficient to press the belts down to a lug level corresponding to that of the upper edges of the bars.

8. In a self-cleaning floor mat, a series of spaced, parallel bars rigidly mounted in a floor with their upper edges substantially flush with the floor surface, a series of power actuated endless belts mounted on end rollers below the floor surface and with their upper runs extending longitudinally between the bars, shoe scraping lugs extending from the outer surfaces of the belts and so formed as to normally project above the level of the top edges of the bars, and means in substantially coextensive supporting contact with the upper run of each belt, such means being yieldable under direct foot pressure on the belt lugs under the area of greatest foot pressure while permitting other parts of the supporting means to also maintain the belt lugs in cleaning contact with shoe surfaces slightly above the upper bar edges, said supporting means for each belt being operative independently of the supporting means for the other belts.

CARL O. SWANSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 823,792 Richardson June 19, 1906 1,019,769 Dalton Mar. 12, 1912 1,152,460 Williams Sept. 7, 1915 1,567,832 Broge Dec. 29, 1925 1,937,258 Vogt Nov. 28, 1933 2,297,107 Magnuson Sept. 29, 1942 FOREIGN PATENTS Number Country Date 48,271 Sweden Apr. 16, 1919 613,979 France Dec. 3, 1926 625,216 France Apr. 19, 1927 

